1. Field
The described technology relates generally to a solar cell and a method manufacturing the same.
2. Description of Related Art
A solar cell includes a silicon substrate, a region of which has a surface that is p-doped, and a region of which has a surface that is n-doped. When solar light is incident on the solar cell, that is, when photons enter into the substrate, electron-hole pairs are formed in the substrate, the generated electrons move to the n-doped region, and the generated holes move to the p-doped region. Due to the movement of the electrons and the holes, a photovoltaic effect is generated, and a potential difference occurs between ends of the p-n junction. In addition, free electrons and holes respectively move to the n-doped region and the p-doped region such that a current is generated. Power is generated from the potential difference, and the current is supplied to a load circuit coupled to the solar cell. Accordingly, solar cell energy is converted to useable electric energy.
A back contact solar cell includes a substrate, a reflection preventing layer, doped regions, a protection layer, and contact electrodes. The substrate is a wafer or a plate of single crystal silicon or poly crystal silicon, and functions as a passage for movement of electrons and holes. The front surface of the substrate is textured, and the reflection preventing layer formed of silicon nitride and/or silicon oxide is formed on the front surface of the substrate. At the back surface facing the front surface, n-doped regions and p-doped regions are alternately arranged. The protection layer is coated on the back surface. The protection layer is partially eliminated so that via holes are formed. The contact electrodes are electrically coupled with the doped regions through the via holes.
The doped regions and the reflection preventing layers of the solar cell are manufactured in sequence by a process for forming the p-doped regions, a process for forming the textured front surface, a process for forming the reflection preventing layer, and a process for forming the n-doped regions. The processes for forming the doped regions include processes for deposition of silicon dioxide layers and processes during which the silicon dioxide layers are selectively etched. The process during which the silicon dioxide layer is deposited is a detailed process during which a doped dioxide silicon including an n-type or p-type material and an undoped silicon dioxide layer are layered using an atmospheric pressure chemical vapor deposition (APCVD) method. The process for selectively etching the silicon dioxide layers includes detailed processes for selectively etching a part of the silicon dioxide layers using etch resist coated on the silicon dioxide layer.
The above-stated manufacturing method of the solar cell may complicate the processes due to increased number of processes for forming the doped regions and increased cost of manufacturing. Thus, simplification of the manufacturing process and manufacturing cost reduction may be desired.
In the solar cell manufactured using the above-stated method, p-doped regions and neighboring n-doped regions have different polarities and contact each other. Thus, electron-hole pairs generated by photons from the contact areas can be easily recombined so that use efficiency of solar energy of the solar cell may be deteriorated. Accordingly, neighboring regions respectively doped with different polarities in the solar cell should be separated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.